"I had to stay in hiding for over a week without taking ARV (antiretroviral) medication. A lot of people are going through the same thing. A lot of people have run to neighbouring countries," Nakato told delegates at an AIDS conference in the Australian city of Melbourne on Monday.

The law has broad support in religiously conservative Uganda, which is among 37 African nations where homosexuality is illegal.

But one of the major concerns of the gathering of 12,000 AIDS activists, scientists and people living with HIV is how the criminalisation of groups at high risk of HIV – such as gay men, sex workers and transgender people – is threatening progress in the global effort to fight Aids.

Prostitution is illegal in 116 countries, and in 78 countries, having a same-sex relationship is a criminal offence.

Major concerns

"We know that criminalisation is bad health policy. It is bad public policy. It doesn’t work to prevent the spread of disease. In fact, it does just the opposite," the US ambassador to Australia, John Berry, told a discussion on the state of legislation in India, Nepal and the United States, among others.

"The global fight against HIV and Aids will not be won by relegating segments of the population to the shadows."

According to the World Health Organization (WHO), female sex workers are 14 times more likely to have HIV than other women, gay men are 19 times more likely to have HIV than the general population and transgender women are almost 50 times more likely than other adults to have HIV.

Yet the same groups are least likely to get HIV prevention, testing and treatment services, theWHO says.

Bad health policy

It’s not only gays and lesbians who feel persecuted in Uganda, Nakato said. Sex workers are among those under pressure from an anti-pornography law, locally dubbed the anti-mini skirt law, which seeks to police erotic behaviour.

"These laws are just there to drive us underground, to harass us," Nakato told the session.

India gay rights activist Ashok Kavi described the "incredible sense of despondency" after India’s Supreme Court reinstated a ban on gay sex in December, following a four-year period of decriminalisation that had helped bring homosexuality into the open in the socially conservative country.

Manisha Dhakal, a Nepalese transgender activist, said certain laws in Nepal – while not criminalising transgender sex workers – were deliberately used against them.

"When we are walking in the street, people are gathered to see us and there are traffic jams because the taxi drivers also want to see us," Dhakal said, adding that the commotion often ended in arrest under the Public Offences Act.

By contrast, the United States is working on changing laws that criminalise HIV transmission, said Nick Rhoades, an American whose conviction for the criminal transmission of HIV in the state of Iowa was overturned last month by the Supreme Court.